U.S. Pat. No. 5,265,924 discloses that a rotatable member 13 and a spring member 15 are disposed within a mounting member 7, and can be operated externally. The retainer 16 is secured on the mounting member 7, so that the rotatable member 13 and the spring member 15 are maintained within the mounting member 7. Referring to such an arrangement, since the retainer 16 and the mounting member 7 are two separate members, the securing effect cannot be assured, and the rotatable member 13 and the spring member 15 are liable to disengage from the mounting member 7 and result in damage or malfunction.
U.S. Pat. No. 5,666,833 was invented by the inventors of present invention, and corresponds to those illustrated in FIGS. 1–8 of the present invention, and is relevant to the first embodiment of the reinforced apparatus for a lever handle of a door lock of ROC (Taiwan) New Utility Model Application No. 83216969. As illustrated in FIG. 1 of the present invention, the primary construction of U.S. Pat. No. 5,666,833 comprises a housing 3, a rotary member 4 and a coiled spring 5; in which the housing 3 includes a disk body formed with a wall 30 and an annular projections 31. A tubular wall 32 is formed between the wall 30 and the annular projections 31. A hole 33 is centrally formed within the annular projections 31. The hole 33 is in communication with two radial notches 34 formed on the annular projections 31. A recess 35 is formed between the annular projections 31 and the tubular wall 32. Two protrusions 36 are formed on the wall 30 and are spaced apart from two positioning holes 37 formed on the wall 30.
The rotary member 4 includes a tubular body having a first end 40 and a second end 41, in which the first end 40 is formed with a radially and inwardly extending tongue 42 and two radially and outwardly extending noses 43. The second end 41 is formed with a radially and outwardly extending annular flange 44. Two axially extending engaging plates 45 are formed on the annular flange 44 with a space between the plate 45 and the outer circumference of the tubular body. Two radially and outward extending lugs 46 are formed on the flange 44 and are spaced apart from the engaging plates 45.
The coiled spring 5 includes two legs 51 and is disposed around the circumference of the tubular body of the rotary member 4, so that two legs 51 of the coiled spring 5 respectively abut against the engaging plates 45 of the rotary member 4.
In an assembling process in a manufacturing factory, as shown in FIGS. 1, 2 and 3, the protrusions 36 of the housing 3 is formed with an inclined angle relative to the wall 30. The coiled spring 5 is disposed around the rotary member 4. The two noses 43 of the first end 40 of the rotary member 4 are then aligned with the two radial notches 34 of the housing 3. The rotary member 4 is then put into the recess 35 of the housing 3, until the noses 43 of the rotary member 4 pass through an outer surface of the annular projections 31 (see FIG. 3). The rotary member 4 is then rotated relative to the housing 3, from a position shown in FIG. 2 to a position shown in FIG. 4. At this time, the space between two legs 51 of the coiled spring 5 disposed around the rotary member 4 is aligned with the protrusion 36 of the housing 3. The protrusions 36 of the housing 3 are then compressed by a fixture (not shown) to reduce the inclined angle between the protrusions 36 and the wall 30, so that two legs 51 of the coiled spring 5 can firmly abut against the protrusions 36 of the housing 3 to form the assembled condition as shown in FIGS. 4 and 5, and so that the rotary member 4 and the coiled spring 5 can be firmly maintained within the housing 3, without axial disengagement from the housing 3.
In practical mounting operation of a user, as shown in FIG. 6, the extending tongue 42 of the rotary member 4 can align with is and engage an axial slot 81 of a driving shaft 8 of a conventional cylindrical lock mounted on a door panel 13. The lever handle 9 then engages the driving shaft 8 in a known manner. Two bolts (not shown) then pass through the through holes 37 of the housing 3 and engage the components located on the other side of the door, so as to securely engage on the door panel 13. In consideration of aesthetic appearance, a mounting cap 10 can be disposed outside of the housing 3 in a known manner to cover the exterior of the housing 3. Alternatively, some other additional inserts can be disposed between the housing 3 and the mounting cap 10 to meet various aesthetic requirements. For example, an annular stuffing member 14 can be provided for increasing the strength of the housing 3, so that the outer surface of the housing 3 will not be indented, when an external force exerts thereon.
As illustrated in FIGS. 7 and 8, when assembled, no matter whether the level handle 9 rotates clockwise or counterclockwise, the driving shaft 8 can be rotated to drive the rotary member 4 to rotate, so that the engaging plate 45 of the rotary member 4 pushes one of the two legs 51 of the coiled spring 5. The other leg 51 of the coiled spring 5 abuts against the protrusion 36 of the housing 3, so that the coiled spring 5 can be deformed to create a resiliently biasing force for returning the lever handle 9 to its original position before it is rotated.
As clearly illustrated in FIG. 7 or 8, when the rotary member 4 is rotated for an angular displacement, the lugs 46 of the rotary member 4 abut against the protrusions 36 of the housing 3, so that the rotational angle of the rotary member 4 is limited, and so that the deformation of the coiled spring 5 is limited within the elastic limit to prevent the internal components of the cylindrical lock from damage due to inappropriate and strong torsion force created by the lever handle 9.